The death toll has risen to 21 in the Oso mudslide, officials confirmed at a briefing Sunday evening, while the number of missing plummeted to 30 over the weekend after many people were found safe.

The Snohomish County Medical Examiner has now officially identified 15 of the victims with another six still unidentified, said Jason Biermann, a program manager with Snohomish County's Department of Emergency Management.

The remains of four more victims were discovered in the massive debris field Sunday, Biermann said.

Officials previously set the number of missing people at 90, but they had said they expected that figure to drop dramatically as they worked to find people and cross-referenced a list that included partial reports and duplicates.

And, underscoring the difficulty of identifying those killed in one of the deadliest landslides in U.S. history, Biermann said crews are not always discovering complete remains.

"Rescuers are not always making full recoveries," he said. "Often, they are making partial recoveries."

Personal items, both large and small, are also discovered in wreckage.

"What we found out here is everything from pictures to gun safes," said Snohomish County Fire District 1 battalion chief Steve Mason.

The items that would later be cleaned, sorted and hopefully returned to families.

Search dogs take a break

Many of the dogs essential in the search for victims of the deadly mudslide take a two-day break, rescue crews said Sunday, as the official death toll rose and more bodies were recovered.

The dogs can lose their sensing ability if overworked in the cold and rain.

"The conditions on the slide field are difficult, so this is just a time to take care of the dogs," said Kris Rietmann, a spokeswoman for the team working on the eastern portion of the slide, which hit March 22 about 55 miles northeast of Seattle and is one of the deadliest in U.S. history.

Dogs from the Federal Emergency Management Agency that arrived more recently will continue working.

Moment of silence

Heavy rains and winds pounded the Oso mudslide debris field Saturday, further slowing the efforts of hundreds of rescue crew members mired in the quicksand-like conditions.

Searchers took time to honor the victims and their families during a moment of silence at 10:37 a.m. - the exact moment the slide occurred last Saturday. Gov. Inslee asked for people in Washington state to take time to pause on Saturday for those lost in the deadly slide.

"The identification process has been very challenging," said Snohomish County Executive Director Gary Haakenson.

The medical examiner will now issue a report to officials once a day at 4:30 p.m., and they in turn will release that information at a single 6 p.m. briefing for the indefinite future.

Foul weather hampering search

Heavy rain and wind made miserable conditions even worse for crews working on the debris field Friday.

"It's made the quicksand even worse. I cannot possibly tell you how long this will last or when or if they will find more bodies. We hope that we do, but right now there's no telling," Haakenson said.

Forecasters say the heavier rain will stick around through at least Monday. The National Weather Service has extended a flash flood watch for the slide area through Monday. Flash flooding downstream to Arlington is possible.

Additional geologists were brought in Friday to determine the threat of another slide.

"At this time, we believe that everybody at the site, from an additional slide potential, is safe. But we want to continue to monitor that," said Snohomish Fire District 21 Chief Travis Hots.

He explained that they've split the slide into two branches: east (Darrington) and west (Arlington).

"It's working well with getting things done and getting the resources that everybody needs on both side of the incident."

He said they're working on an emergency road for emergency vehicles only.

Search teams are describing horrific conditions as they wade through the widespread debris field at the Oso mudslide.

"If you could imagine houses, trees, and a bunch of mud put into a blender, run for a bit, and then dumped back on the ground," said National Guard Master Sgt. Chris Martin. "It's absolutely devastating."

He and Senior Airman Charlotte Gibson are part of the Search and Rescue Extraction Team.

"It's almost impossible. You'll fall in waist deep or knee deep in some areas... we just keep pushing on as slowly and meticulously as we can so we don't miss anything," said Gibson.

The pair explained when they discover human remains, they'll use GPS to mark the location and then call the command center, which will send a dog or other support.

"You start with how many people are there, how many people aren't there and that's your base number," explained Tom Miner with FEMA's Urban Search and Rescue Team. "And then there's the unknown of how many people were in there that we don't know anything about. Will you ever get an accurate number? It took us weeks to get an accurate number in Oklahoma City and I'm not sure we ever got an accurate number in the World Trade Center."